iBasso PB-2 Pelican fully balanced portable, DB-2 Dac . . HiFlight recommended op amps page 16. .
Dec 5, 2017 at 12:29 AM Post #1,516 of 1,604
That is a nice looking battery pack inside the PB2.

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Dec 7, 2017 at 4:57 PM Post #1,517 of 1,604

Those are 3.7V nominal, per cell, so the four of them are giving you 4.2V x 4 = 16.8V for the first couple of minutes of play, but then it will rapidly come down below the 16V max. iBasso specifies, so no problem there, really.

The best part is that for the majority of your discharge cycle, you will have 3.7V x 4 = 14.8V, which in my experience with external supplies, would be audibly better than the 12.6V (nominal) that we get with the original 3-cell battery.

Well done!

Watch out to avoid deep discharging any one cell below 3.0V. I doubt the charge circuit in the PB2 is intelligent and those individual batteries probably don't have any built-in protection. Over time, one cell can end up getting "out of sync" with the other cells, in terms of voltage at both the top and bottom of a cycle. This is less likely to happen if you avoid deep cycling the pack. (Probably stuff a guy with your DIY skills already knows...)

Mike
 
Dec 29, 2017 at 8:50 PM Post #1,519 of 1,604
wooooooooooooooooooooooooooooooow

I got another PB2, and this time the OpAmps are in correctly! No dummy buffers how ever as I'm going to be using this EXCLUSIVELY for my hard to drive open backs, like my HE 4, Pre Fazor LCD 2 and my AKG K240 Sextett, so far with the Sextett... WOOOOW It's SOOOOOOOOOOOOOOO Much quieter than my last one was. Granted I've got a Schiit Etir, new Power Cables for everything and an upgraded Power Conditioner, but WOW this thing is SUPER quiet. I am using the energizer battery pack as well. If I'm taking my big Heavy OLD fragile planars out the house than I'll have no issues carrying around... the Battery for my Amp [which is a bit bigger than the amp itself]

All in all wooooooooooow, just WOW Super impressed with this bad boi! An I paid about the same this time as I did the first time I got it! I got lucky and found one on eBay, but just wow! It's ALMOST as good as my NFB10ES2 with Phase Reversal... ALMOST and it's portable ;3 have to say it's wonderful to be back in the Club again!

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Sadly only stock internals for now, aside from the entirely separate battery
 
Jan 2, 2018 at 9:25 PM Post #1,521 of 1,604
^ Happy post!

Puts a smile on my face!

Thanks!

Mike

Me too! I was worried I wouldn't like the sound with the High Current buffers over the Dummy, but I think the improvements of the battery kinda negate what ever losses the non Dummy Buffers introduce. Plus my portable set up is super specialized! The Head Amp Pico Power [isn't nearly as powerful as I wanted it to be] does a great job with my dynamics, and the PB2 handles my Planars and the AKG K240 Sextett! Plus I have some nice hiRose 6pin to dual 4pin XLR adapters I can use again!
 
Jan 9, 2018 at 11:48 AM Post #1,523 of 1,604
I got the DB2 not long ago and didn't like what I heard. Sounded dull and I had to turn up the volume on the PB2 to hear details. So I swapped out the opamps in the DAC using two Muses 8832. What a difference it has made. Subbass is cleaner, mids and highs are all there at lower volumes. Still waiting on the Hirose connectors and mogami quad cable to come in, for me to the built the balance cables to connect the PB2 and DB2.
I also have a pair of WM8741 on order to stick into the DB2. Got inspired doing that, seeing that it can be done @plutonim
 
Jan 19, 2018 at 11:10 AM Post #1,525 of 1,604
Sooooo, I didn't want to mess with the DB2 yet, and I opted to swap out the dac inside my D7 Sidewinder instead. The "new" WM8741 does sound different vs the 8740 it replaced. Nicer topend and more "analog" overall. You would think both dacs would sound the same, with the 8741 just having more features. But that is not what my ears tell me. Anyways, sooner or later I'll be changing out the ones in the DB2.

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Jan 23, 2018 at 4:06 AM Post #1,526 of 1,604
I had some time again to mess around with cable upgrades inside the PB2 and I think I found a happy medium. Mixed copper with silver over the just the sliver alone. Got my deep sub bass back, along with the benefits the silver brought to the table.
^ Dude! (I'm envying your skills again!)

Check this out :)
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Jan 23, 2018 at 1:31 PM Post #1,528 of 1,604
Huh you know I have no battery in my unit... I might be able to fit in a set of those bad bois... I actually have the PLAY on loan with a set of both their red Vivids and the orange Classics, I'm a little scared to try them lol as then I'll need to get them

@plutonim what are those little bendy things your using?
 
Jan 23, 2018 at 1:39 PM Post #1,529 of 1,604
Huh you know I have no battery in my unit... I might be able to fit in a set of those bad bois... I actually have the PLAY on loan with a set of both their red Vivids and the orange Classics, I'm a little scared to try them lol as then I'll need to get them

@plutonim what are those little bendy things your using?


Those bendy thingies are just short extensions. Easy to make if you have some time. I've made some before in my other projects. Even added a Wima cap in some.

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Jan 23, 2018 at 1:41 PM Post #1,530 of 1,604
What did you find adding the wima what I imagine is a bypass cap, into the mix?

Also my soldering skills are a bit lacking, I'm curious though would you care to make a set for me?
 

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